1. Field of the Invention
The present invention relates to a device for the hand-guided movement of loads by means of a retaining or gripping element as a lifting aid, which retaining or gripping element is attached to a load-bearing rope. In such lifting aids, a load-bearing rope is guided along a cantilever, which is horizontally aligned, for example, which can be wound in or unwound over a cable or rope winch to in order to lift loads to be conveyed. As retaining element, various types of grippers are used, such as, for example, vacuum grippers, by means of which the loads can be attached to the end of the rope by an operator. The cantilever of the load-bearing apparatus generally can be swiveled to the side, and a rope articulation point on the cantilever is adjusted via an adjustment mechanism in the longitudinal direction of the cantilever, so that the load can be shifted from an original site to a destination site. After picking up the load by means of the retaining or gripping element, the operator of the device manipulates the load by hand in order to shift it to its destination site and deposit it there.
2. Description of Related Art
EP 1 551 747 B1 shows a device for preventing instabilities in such lifting aid devices, which comprises a trolley that can be shifted on a vertical support. A rope winch for a load-bearing rope is attached to the trolley. If an operating person wishes to perform a shifting of a load that has been picked up, the shifting is started by a sideways pushing of the load, so that the load-bearing rope is deflected from the vertical into a slanted alignment. Depending on the measured deflection, the magnitude and direction of the shift of the laser are determined. The trolley is then activated in the direction towards an adjustment of the rope angle with respect to the vertical. The speeds of the trolley is determined based on the direction and magnitude of the deflection angle of the rope. The rope winch is moved together with the trolley along the vertical cantilever. Therefore, a correspondingly dimensioned trolley and load-bearing apparatus as well as a comparatively large drive for the adjustment of the trolley are necessary.
The present invention is based on the problem of providing a lifting aid which can be activated manually and which has a simple, light-weight and space-saving design.
This problem is solved with a device having the features of claim 1. Advantageous designs and refinements of the invention are the subject matter of the dependent claims.
The device according to the invention comprises a load-bearing apparatus with at least one cantilever which preferably extends horizontally and over which a load-bearing rope or load-bearing cable is guided from sides of a rope winding device (for example, a rope winch which is driven or can be driven) by means of a rope articulation point which can be shifted or adjusted particularly along the cantilever. At the free end of the load-bearing rope, a retaining or gripping element is attached, which is adapted for picking up loads, for example, in the form of a gripper, a hook or a suction gripper.
A sensor is provided for measuring a rope angle of the load-bearing rope relative to the vertical, and a controller is also provided, which is connected to the sensor and works together with said sensor. Said controller is designed for the simultaneous control of a shifting of the rope articulation point and of a rope length of the load-bearing rope on the basis of a measured rope angle. In particular, by means of the controller, both the rope winding device and also at least one actuating drive can be activated for the shifting of the rope articulation point as a function of the rope angle measured with the sensor.
If an operating person, by applying a lateral force to the load, moves the load-bearing rope from the vertical, the sensor acquires the corresponding deflection angle of the load-bearing rope from the vertical. The acquisition values of the sensor are transmitted to the controller. By means of the controller, an automatic adjustment of the rope articulation point along the cantilever of the load-bearing apparatus is produced. At the same time, the controller controls, in accordance with an adjustment of the rope articulation point, the rope winding device for the adaptation of the effective rope length of the load-bearing rope. This makes it possible, in particular, to keep the load at a constant height on the retaining element of the device. In this manner, the rope winch can be mounted stationarily, for example, on a vertical support, without the adjustment of the rope articulation point leading to an adjustment of the height of the load to be carried. On the cantilever itself, only the rope articulation point which can be adjusted by means of an actuating device is provided.
By means of the controller which is adapted especially for this purpose and connected to the sensor for the acquisition of the rope angle, an activation of the rope winding device thus occurs in such a way that, when the rope articulation point on the cantilever of the load-bearing apparatus is adjusted as a function of the rope deflection angle, the load-bearing rope is wound in or unwound in accordance with the degree of the adjustment, so that, while the carried load is indeed moved with the shift of the rope articulation point, the rope length between the rope articulation point and the carried load remains constant. Therefore, by means of the controller, as a function of the rope angle acquired by the sensor, not only the movement of the rope articulation point on the load-bearing apparatus is actively controlled, but, in addition, a winding up or unwinding of the load-bearing rope is produced in order to maintain the carrying height by the rope winch.
The rope winding device is mounted in particular stationarily on the load-bearing apparatus. For example, the rope winding device is attached at a rear end of the cantilever or on a vertical support of the load-bearing apparatus.
The controller comprises, in particular, a means for the active tracking of the rope articulation point on the cantilever of the load-bearing apparatus in a direction of adjustment of the rope angle of the load-bearing rope toward the vertical. If an operator of the device moves a held load in a certain direction (for example, forward), then the sensor acquires the magnitude of the angle of the load-bearing rope and transmits this value to the controller. In the controller, an algorithm, for example, is stored which produces a corresponding adjustment of the rope articulation point in the given direction (for example, forward). For this purpose, the rope articulation point is provided with a corresponding drive or actuating drive, by means of which a corresponding shift of the rope articulation point can be brought about, in such a manner that the load-bearing rope is moved back again towards the vertical.
The controller comprises, in particular, a means for keeping the rope length between the load and the cantilever constant in the case of a sideways shift of the load by a user. As a result, it is possible to ensure that the load is always at the height above the ground selected by the user. This facilitates the handling of the device according to the invention by a user, who needs to use less force when shifting the loads.
Preferably, a trolley which is adjustable on the load-bearing apparatus and which can be activated by the controller is provided between the rope articulation point and the cantilever. The trolley comprises, in particular, a drive means for shifting in the longitudinal direction of the cantilever.
The rope articulation point can be implemented, for example, by a deflection roll. The deflection roll is arranged on the trolley, for example. A trolley that can be driven automatically can be formed, for example, from a base body having a C-shaped cross section and used in a corresponding inverted T profiled part or H profiled part of the cantilever.
When an adjustment of the load-bearing rope from the vertical is acquired, the driven trolley is automatically moved by the controller in the direction which leads to a return of the load-bearing rope to the vertical (adjustment). The forces for moving the rope articulation point and the cantilever are thereby decoupled from the user, which is advantageous particularly in the case of rapid handling procedures, since the inert mass that has to be moved is reduced as a result.
In a further design, it is possible to provide actuating drives connected to the controller for adjusting the rope articulation point in the longitudinal direction of the cantilever and/or in a direction transverse to the longitudinal direction of the cantilever. For example, the trolley can be shifted and/or the arrangement (for example, rotation angle) of the cantilever on a support can be changed. In this manner, an active tracking of the position of the rope articulation point from front to back or from back to front, and optionally also sideways, can be performed by the cantilever of the load-bearing apparatus.
The cantilever can be arranged rotatably on a support, for example, on an axle that can be actively rotated about a vertical support. In this manner, a two-dimensional movement can be implemented with the cantilever.
Then, for example, two different actuating drives can be present, each connected to the controller which receives the respective rope angle, as input signal, from the sensor.
Advantageously, the load-bearing apparatus comprises a cantilever that can be swiveled sideways (particularly in the horizontal plane) on a vertical support, which is provided with an actuating drive for the active turning of the cantilever about a vertical rotation axle. The load-bearing apparatus can a comparatively simple structural design in the form of a substantially L-shaped lifting beam.
The load-bearing apparatus can also comprise a pivot arm cantilever with an additional vertical rotation axle on which a pivot joint which can be adjusted via an actuating drive is provided. In this manner, the radius of action of the device is further increased.
It is also conceivable for the load-bearing apparatus to comprise a scissor cantilever, in which two cantilevers or load-bearing arms coupled to one another by a joint are provided.
The sensor for the acquisition of the rope angle relative to the vertical can be formed as a one-dimensionally measuring deflection sensor or angle sensor, which is arranged at a predefined distance beneath the rope articulation point adjoining the load-bearing rope. Such a one-dimensional angle measurement of the rope angle relative to the load-bearing rope can be implemented using a so-called line sensor, for example. For the measurement of the rope angle, a laser can also be used, which is directed from top down onto the operating unit or the gripping element, in order to measure, in this manner, the deflection of the load-bearing rope from the vertical. Such a sensor can also be used advantageously for the acquisition of the rope length between the rope articulation point and the load to be carried.
According to another advantageous design of the invention, the rope articulation point is formed as a deflection roll with lift-off protection. This reduces the frictional forces that form at the time of the adjustment of the load-bearing rope on the rope deflection point. As a result, the winding up and the unwinding of the load-bearing rope are further accelerated.